Picture frame



FIG. 1 is a front, right, top perspective view of the picture frame;

FIG. 2 is a front elevation view;

FIG. 3 is a right side elevation view;

FIG. 4 is a back elevation view;

FIG. 5 is a top plan view; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a picture frame, as shown and described. 